1. Field of the Invention
The present invention relates to human T-lymphotropic virus (HTLV). More particularly, the present invention relates to antigenic fragments of HTLV.
2. Description of the Related Arts
Human T-lymphotropic virus (HTLV) classified into Retroviridae was the first human retrovirus to be isolated. HTLV type I was first isolated in 1978 whereas HTLV type II was in 1982. HTLV is spread by sexual contact, from mother to child and through contaminated blood product. It is endemic in southern Japan, Caribbean, South Africa and Melanesia. To avoid viral transmission, screening of blood donations for HTLV is now routinely carried out in many countries. Since 1996, antibodies of HTLV-I and HTLV-II have been screening by ELISA and western blotting in Taiwan.
The preliminary screening of HTLV is carried out by ELISA, and a final diagnosis can be made by western blotting and polymerase chain reaction. The commercialized HTLV assay utilizes viral total lysate as antigen to detect specific antibodies from carrier blood. For higher sensitivity and specificity, a peptide fragment of viral envelop can be used as an additional antigen. The preparation of viral total lysate is complicated and has a potential risk; there is, therefore, still a need for a safe and effective HTLV antigen.